Pressure Relief Valve - Pentair Pool Products MASTERTEMP 250K BTU/HR Installation And User Manual

PRESSURE RELIEF VALVE

Canadian code requires and some U.S. local codes may
require installation of a pressure relief valve. Purchase
separately and install a 3/4" pressure relief valve comply-
ing with the ANSI/ASME Boiler and Pressure Vessel Code,
having a capacity equal to the Btu/hr rating of the heater.
The relief pressure of the valve MUST NOT EXCEED 50
PSI.
A 3/4" NPT connection is provided in the manifold for
installing a pressure relief valve. The relief valve must be
installed vertically. To install the valve, use a 3/4" brass
nipple and elbow (user supplied), as illustrated in Figure
19. No valve is allowed to be placed between the mani-
fold adapter and the relief valve.
To avoid water damage or scalding from operation of the
relief valve, install a drain pipe in the outlet of the pres-
sure relief valve that will direct water discharging from
the valve to a safe place for disposal. Do not install any
reducing couplings or valves in the drain pipe. The drain
pipe must be installed so as to allow complete drainage
from the valve and drain line. The relief valve should be
tested at least once a year by lifting the valve lever.
Raise Pressure
Turn star wheel to raise pressure set
point if pressure switch is more than
2 feet (0.6M) below water level
Lower Pressure
Turn star wheel to lower pressure
set point if pressure switch is more
than 5 feet (1.5M) above water level
FIGURE 18: Water Pressure Switch Adjustment
18
Explosion hazard. Any heater installed with
WARNING
restrictive devices in the piping system downstream from
the heater (including check valves, isolation valves, flow
nozzles, or therapeutic pool valving) must have a relief
valve installed as described above.
Relief Valve Installed
User
supplied
pipe
fittings
FIGURE 19: Relief Valve
A reference scale is on the
back of pressure switch
2681 1096
Pipe relief valve discharge
to a drain or other safe
disposal site.
Star wheel
Star wheel